Nutrient Dynamics Associated with Leaching and Microbial Decomposition of Four Abundant Mangrove Species Leaf Litter of the Sundarbans, Bangladesh

Release of nutrients and organic matter from mangrove litter during the leaching and decomposition processes play an important role in the biogeochemical cycling in mangrove ecosystems. Mass loss and nutrient dynamics associated with leaching and microbial decomposition of leaf litter of Heritiera fomes, Excoecaria agallocha, Ceriops decandra and Xylocarpus mekongensis were studied in the Sundarbans. The initial mass of H. fomes, E. agallocha, C. decandra and X. mekongensis leaf litter was significantly decreased to 11 %, 18 %, 21 % and 19 % respectively after 168 h of leaching process. Irrespectively, mass loss due to the microbial decomposition was higher for E. agallocha (97 %) followed by X. mekongensis (74 %), C. decandra (44 %) and H. fomes (42 %) after 7 months. Highest amount of N (3.29 mg/g) was released from leaf litter of C. decandra and the highest amount of P (1.69 mg/g) and K (16.36 mg/g) was released from E. agallocha. Comparatively higher amount of N (6.36 mg/g), P (2.68 mg/g) and K (16.41 mg/g) was released from the leaf litter of E. agallocha than others. Our results are useful for estimating the total flux of nutrients of mangrove forest ecosystem, especially where the studied mangrove species occur abundantly.